R-Patz mingled with fans when eating at a comfort food diner over the weekend in Washington D.C.! And he even gave one teen girl the best birthday surprise ever! Read on for ALL the exclusive details!

The 25-year-old shocked patrons dining at The Majestic — an upscale diner in Alexandria, Virginia — when he rolled up with five unidentified friends on April 28, a source tells HollywoodLife.com exclusively.

Rob was with a party of six — all men — and wined and dined for three hours on Saturday night.

And even though girlfriend Kristen Stewart, 22, was nowhere in sight — he stole another girl’s heart! R-Patz signed a menu for 13-year-old Eve Armstrong, Majestic chef Cathal Armstrong‘s daughter!

‘To Eve, Happy Birthday. Robert Pattinson x,” Rob wrote.

He’s so sweet!

Rob was reportedly very friendly to everyone in the restaurant. He mingled with patrons at the bar while waiting for a table, the source tells us. And unlike his Twilight character Edward — it’s safe to say R-Patz is not on a strict diet.

R-Patz indulged in a medium-rare “All Natural Virginia New York Strip Steak” which costs $27 and is served with “Majestic butter, hand-cut fries.”

What do you think, HollywoodLifers? Is Rob the sweetest celeb ever? Vote and weigh in below.